drivers: Remove BKL from pc8736x_gpio

cycle_kernel_lock() was added during the big BKL pushdown. It should
ensure the serializiation against driver init code. In this case there
is nothing to serialize. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091010153350.127093710@linutronix.de>
Acked-by: Jim Cromie <jim.cromie@gmail.com>